The present invention relates to light sensors and particularly sensors used in light tracking devices.
With the current shortage and cost of fossil fuels, there is an increase in interest in alternative energy sources including solar energy. It is well known that for solar collectors to be efficiently used for energy transfer, it is necessary to direct the solar collector toward the sun as it moves through its daily arc of travel. This naturally maximizes the amount of radiant energy absorbed by the collector permitting most efficient utilization of the radiant energy from the sun.
There have been several relatively complicated solar tracking devices proposed, some of which employ light sensing devices permitting the tracking of the sun and some of which simply are motorized on a time basis to scan the arc of travel of the sun through the sky each day. Representative of existing solar tracking devices are U.S. Pat. Nos. 4,151,408; 4,158,356; 4,159,710; and 4,091,799. For the most part the prior art either incorporates a specialized solar tracking device integrated with the collector configuration and therefore not usable for a variety of different collectors or they have been relatively complicated and therefore costly.
There exists a need therefore for a relatively inexpensive sensor which can be used for providing signals controlling a solar tracking device for a solar collector.